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Orange Skies

January 24, 2010

Most of the night sky is a study in black and white -- a few pale points of light against a velvety background. Tonight, though, the sky offers a connect-the-dots study in color: a zigzagging line of four star-like points that all shine in shades of orange.

The brightest of the bunch is the planet Mars. It's well up in the east by two or three hours after sunset. It outshines everything else in the sky at that hour except the Moon, so it's hard to miss. And because it's so bright, its color is hard to miss, too. We'll have more about Mars tomorrow.

The faintest member of the quartet is almost directly above Mars: Pollux, one of the "twin" stars of Gemini. It's a stellar giant -- it's puffed up like a big balloon, causing its outer layers to cool. That's what gives the star its color -- cooler stars are orange or yellow, while hotter ones are white or blue.

Next, take a good jog to the right for Betelgeuse, at the shoulder of Orion. It's a supergiant -- one of the biggest stars in the galaxy. It's so big that it's clearly visible across several hundred light-years of space.

Finally, go farther to the right and up a good bit for another giant: Aldebaran, the eye of Taurus, the bull. It's not far from the Moon, so some of its color might be washed out by the moonlight. If you look carefully, though, you should still see a hint of orange, making Aldebaran one of four colorful beacons shining through a monochrome sky.

Script by Damond Benningfield, Copyright 2009

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